Automatic sprinkler.



A; L LOEPSINGER. AUTOMATIC SPRINKLER. AF'PLICATI O N FILED MAR. 30, l9l8.

. Patented Jan. 7, 1919.

ALBERT J. IiOEPSINGER, OF EDGEWOOD, RHODE ISLAND, ASSIGNOR T0 GENERALFIRE EXTINGUISHER COMPANY, OF PROVIDENCE, RHODE ISLAND, A CORPORATION OF NEW YORK.

-/ To all whom it may concern:

Be it known that I, ALBERT J. Lonrsnvenn, citizen of the United States, residing at Edgewood, in the county of Providence and State of Rhode Island, have invented certain new and useful Improvements in Automatic Sprinklers, of which the following is a specification.

My invention relates to automatic sprinklers of the type in which the sprinkler is normally held closed by means of a frangible vessel nearly filled with a liquid and is permitted to open, when sufiiciently heated, by the fracturing of the vessel resulting from the expansion of the contained liquid. The object of the invention is to provide a sprinkler of this type inwhich the vessel when fractured will be instantly and effectively shattered, so that no part' of it can remain as an obstruction to interfere with the opening of the sprinkler.

The operation of my sprinkler is based on the fact that the boiling point of a liquid rises as the pressure to which the liquid is subjected increases, and I- take advantage of this fact by employing in the frangible yes sel a liquid the boiling point-of which at atmospheric pressures is lower than the in tended operating temperature of the sprinkler. When the sprinkler is heated, as by exposure to a fire, the vapor pressure in the frangible vessel increases as the temperature rises and as the pressure increases the boiling point of the liquid rises, the vapor of the liquid being condensed as the liquid expands until eventually the vessel is first filled and then fractured by the expanding liquid. Before fracture occurs, however, the temperature of the liquid is raised above its boiling point at atmospheric pressures, and the result is that when the vessel is fractured and the internal pressure is thereby relieved the heat stored in the liquid above the amount needed fqr boiling it at atmospheric pressures expends itself latent heat of vaporization and instantly converts a por tion of the liquid into vapor, the expansive force of which effectively shatters the vessel.

A form of sprinkler in which my invention may be embodied is illustrated in the accompanying drawings, in which the figure shows the sprinkler in vertical section.

The sprinkler illustrated comprises a body portion 2, a yoke 3 screwed at one end into the body portion 2, a resilient valve Specification Letters Patent.

AUTOMATIC /SPRINKLER.

Patented Jan. *7, 1919.

Application filed March 30. 1918. Serial No 225.747.

seat 4' clamped between the yoke and body portion and having a central perforation, a valve 5 resting on the valve seat 4 and normally closing the perforation therein, and a deflector 6 carried by the free end of the yoke, all of the parts above mentioned being of familiar construction. .In addition cast integral with the yoke 3, a cap-piece 8 resting 'on and centered by the valve5, and a frangible vessel consisting of a glass bulb 9 interposed between the cap-piece 8 and the ling 7 and serving as a strut to hold the valve 5 against its seat. The neck 10 of the bulb projects upward beyond the ring 7 and is received Within a space left in the upper end of the yoke 3, whereby it is protected from accidental breakage, and the rounded bottom of the bulb is received within and kept in position by a concavity formed in the top of the cap-piece 8 and conforming to the contour of the'bulb, the parts being so proportioned that when they are assembled and the yoke is screwed into the body portion to clamp the valve seat 4 in place the latter is flexed slightly by the valve 5 and held tightly against the valve by its own elasticity.

The bulb may be so prepared that it will be fractured at any desired temperature at which automatic sprinklers are required to operate and any one of a variety of liquids may be used in the bulb, provided that the boiling point of the liquid employed is lower than the temperature at which the sprinkler is designed to operate. In the case of sprinklers intended to operate at the usual temperature of 165 F. the liquid which I prefer to employ is ordinary ether, which has a boiling point of about 95 F at atmospheric pressures. This boiling point is so low, however, that effective shattering of bulbs containing other can be obtained at temperatures very much lower than 165 I 1, so'that by using ether in the bulb I ani able to produce sprinklers adapted to operate at any desired temperature within ,a wide range not covered by sprinklers of the fusible-solder type. For sprinklers intended to operate at higher temperatures than 165 F. a liquid having a higher boiling point than ether is preferable, in order that the bulb may not be subjected to excessive internal pressure prior to fracture.

The bulb is prepared by first completely the sprinkler includes a ring 7, preferably.

. pand and overflow, leavin filling it with the liquid and then heating it and its contents to a temperature, determined by trial, which is less than the intended operating temperature but bears a definite relation to it, depending upon the elasticity and co-efiicient of thermal expansion of the material of which the bulb is made. This heating causes the liquid to exin the bulb a proper amount of the liquid to fracture it when heated to the intended operating temperature. The neck of the bulb, which preferably has a capillary here, is then sealed, after slight cooling to free the neck from liquid at the point of sealing, and after this has been done the subsequent cooling of the bulb to normal temperature results in the contraction of the contained liquid,

leaving above it an expansion space which contains only the saturated vapor of. the liquid at a pressure corresponding to the temperature of the liquid. The bulb is then assembled with the other parts of the sprinkler as already explained.

If thetemperature reached by the liquid during the preliminary heating above described is above the boiling point of the liquid the heating should be carried on in a closed vessel at a pressure high enough to prevent actual boiling, which would be likely to expel too much liquid. I have found, however, "that there is a sufficient margin between the temperature reached during the preliminary heating and the.

fracturing temperature of the bulb to permit the employment ofa liquid having a boiling point which is at or slightly higher than the temperature of reliminary heating, without materially a ecting the operation of the sprinkler in the manner hereinbefore explained. When such a liquid is used the preliminary heatin can be carried on under ordinary atmospheric pressure, which simplifies the operations involved in preparing the bulb.

While my invention is particularly adapted and intended for. use in automatic sprinklers, it will be evident that the above-described frangible vessel and its contents, in which the novelty of my invention primarily resides, constitute an article of manufacture which can be used as a thermostatic release in a variety of devices intended to operate at a predetermined temperature.

I claim:

1. An automatic sprinkler comprising, as a means for normally holding the sprinkler closed, a frangible vessel containing a liquid volume that the temperature of the liquid when heatedsufiiciently to fracture the ves sel by expansion is higher than its boiling point at atmospheric pressures.

3. An article of manufacture consisting of a frangible vessel containin a liquid and an expansion space of such re ative volume that the temperature of the liquid when heated sufliciently to fracture the vessel by expansion is higher than its boiling point at atmospheric pressure.

- Signed at Providence, Rhode Island, this 28th day of March, 1918.

' ALBERT J. LOEPSINGER. 

